1. Field of the Invention
An aspect of the present invention relates to a central heating and hot water supply system for receiving a heat source such as steam or high-temperature water obtained from a medium- or large-sized boiler, a heat source obtained from nature such as sunlight, or a heat source obtained from waste heat of an electric generator or boiler, producing hot water through a heat exchange, and supplying the hot water from small- and medium-scale buildings to large-scale buildings using a central supply method. More particularly, an aspect of the present invention relates to an energy-saving central heating and hot water supply system which can simplify pipeline equipment for supplying hot water to each household by removing a hot water supply pipe connected to each household from a machine room, and which can save energy used for heating and hot water supply by circulating heating water used for production of hot water through a bottom coil installed in each household or floor.
2. Description of the Related Art
In recent large-scale apartment complexes or medium- and large-scale buildings, heating and hot water supply systems have not been established as individual heating and hot water supply systems but been established as central heating and hot water supply systems. In the central heating and hot water supply system, heating and hot water is supplied to each household or floor through a common piping network by establishing a common heating system for the entire complex, and the hot water supply is generated by heating water supplied to the system to an appropriate temperature through a heat exchange between hot water and the supplied water and then supplying the heated water to each household or floor through the piping network.
In the central heating and hot water supply system, heat source equipment having relatively high efficiency is commonly used for many users, and a professional manager maintains and repairs the heat source equipment. Thus, the central heating and hot water supply system can actively prevent the decrease of efficiency, caused by the long continuous use of the heat source equipment, and reduce the entire capacity of the heat source equipment, as compared with the individual heating and hot water supply system. Further, since heating source equipment is concentrated on one place, it is easy to deal with an emergency situation such as a fire.
However, in the central heating and hot water supply system, the installation area of equipment for heating and hot water supply increases, and the cost of equipment increases more than that in the individual heating and hot water supply system. Further, civil complaints may occur due to an increase in cost of piping equipment and occurrence of maintenance and operating expenses.
FIG. 1 is a structural view of a conventional central heating and hot water supply system.
In the central heating and hot water supply system, a heat source such as hot water, medium temperature water or steam produced in a heat producing facility 10 is supplied to a machine room 20 located at a structure such as an apartment or building, and the heat source supplied to the machine room 20 is supplied to a heat exchanger 30 for heating and a heat exchanger 40 for hot water supply so as to produce heating water and hot water. Then, the produced heating water and hot water are supplied to each household.
In addition to the heat exchanger 30 for heating and the heat exchanger 40 for hot water supply, a water supply pump 50, equipment such as a heating circulation pump 31 and a hot water supply circulation pump 41 are provided in the machine room 20. The heating water and hot water produced in the machine room 20 are supplied to each household via machine-room pipes, common pipes and horizontal and vertical pipes installed in each structure.
However, in the conventional system configured as described above, the hot water produced in the machine room flows for a long distance through the machine-room pipes, the common pipes and the horizontal and vertical pipes, and is then supplied to each household. Therefore, heat loss through the pipes is large (it is typically identified that up to 10 to 30% of the heat of the entire hot water supply energy is lost), and power consumption for fluid transfer is large. Since more pipe installation cost is required to connect between the machine room and each household, the cost of construction work increases. Further, the effective space of the structure is reduced due to installation of a medium- or large-sized heat exchanger and pipe equipment and machine room space, a basement, and a pipe duct.
An integrated piping system of an apartment house and building has been disclosed in Korean Patent Laid-Open Publication No. 2010-0118473.
FIG. 2 is a structural view of the public housing and building integrated piping system.
The public housing and building integrated piping system includes an integrated heat exchanger 110, an integrated supply pipe 120, an integrated return pipe 130, a supply pipe 140, a return pipe 150, a hot water supply pipe 160, a hot water return pipe 170, a hot water heat exchanger 180, and a cooling/heating controller 200. The integrated heat exchanger 110 supplies high-temperature water produced by a heat producing facility and heated water heat-exchanged in the integrated heat exchanger 110 to each household or floor in an apartment house. The integrated supply pipe 120 supplies the heated water heat-exchanged in the integrated heat exchanger 110. The integrated return pipe 130 is connected to the integrated supply pipe 120 so as to collect the heated water. The supply pipe 140 is installed for each household or floor in the apartment house and is branched from the integrated supply pipe 120 so as to supply the heated water. The return pipe 150 is installed for each household or floor in the apartment house and is branched from the integrated return pipe 130 so as to collect the heated water. The hot water supply pipe 160 is branched from the supply pipe 140 so as to supply the heat water. The hot water return pipe 170 is branched from the return pipe 150 so as to collect the heated water after heat is exchanged. The hot water supply heat exchanger 180 is connected to the hot water supply pipe 160, the hot water return pipe 170 and a water supply pipe 101 so as to supply hot water by performing a heat exchange between heated water transferred through the hot water supply pipe 160 and cool water supplied through the water supply pipe 101, and discharges the heated water heat-exchanged with the cool water to the hot water return pipe 170. The cooling/heating controller 200 controls the flow rate of the heated water supplied to the supply pipe 140 and the hot water supply pipe 160.
The integrated piping system of an apartment house and building configured as described above uses an integrated pipe for heating and hot water supply, so that it is possible to decrease building construction cost, equipment construction cost, and equipment management and maintenance cost.
However, since the integrated pipe system described above supplies both heating water and hot water through the integrated supply pipe, a large-capacity pump is required in order that the flow rate required in the heating and hot water supply can be sufficiently supplied, and the diameter of the pipe is necessarily increased. Further, low-temperature water is locally heated by many heat sources for hot water heating. For this reason, if the thermal capacity of the heated water is not efficiently radiated, the effect of improvement may be insignificant. Furthermore, unreasonable energy loss may be caused due to excessive equipment capacity, or the like.
That is, since heated water is collected at a relatively high temperature in the process of collecting the heated water to the integrated heat exchanger after heating or producing hot water through the heat exchanger, the integrated pipe system in the apartment house and building has a problem of limited energy savings, such as a large amount of heat loss due to a great difference in temperature between the inside and outside of the pipe. Since heating water and hot water are separately heated through the integrated pipe, more heat capacity is required in each household or floor. Therefore, various problems may occur due to surplus heat capacity or flow rate supplied when the hot water supply and heater are not simultaneously used to the maximum load, particularly when demand on hot water supply is decreased or does not occur. Accordingly, a system is required to solve such problems, but a control method is not specified. As a result, floor noise may occur due to an increase of flow velocity in a heating pipe installed in the floor, caused by an excess amount of circulation water, and the total heat effectiveness of radiant heating in the floor may be decreased.